Stovepipe damper



Nov. 9,

BRUNO MARTIN, F SAGIHAW,

P it il LEICHIGAN.

STOVE-PIPE DAMPER.

Application filed July 31,

This invention relates to an improvement in stove pipe dampers andventilators of the type characterized by section of stove pipe formedwith an annular ser es of perforations for admission ofair and hollowtruncated cone open at the top and bottom and mounted in {god posit-ioninside the pipe, the. large or lower end ofthe cone connected to thesides of the pipe below the perforations. These devices usually have anannular slide provided with openings corresponc. 7, those in the pipe,

llily pr, nt invention is an improvement upon the usual constructionabove described in that overheating of the stove pipe above the openingsis prevented, because the tlliCll in through the penings is guided in athin layer alohg the heating surface of the truncated cone and the airso admit-ted is :ed with the rising hot gases where they eineroe fromthe top of the cone, the mixture 31 1' place near the middle. of thestove e instead of occurring as heretofore, across the entire area ofthe pipe.

1 us mix of a central column of hot g with a thin annular layer ofheated outside air, and accomplishing the mixing 'n h middle of thestove pipe, improves Moreover, eddies in the upwardly ascending gas current are avoided and the effectiveness of the traught is improved whileincreasing the rate of removal of air from the appartment in which thepipe is located.

I accomplish these results by adding to the usual perforated pipe andthe hollow cone, as heretofore combined, a second hollow cone which issecured at its lower end to the interior of the pipe, above the row ofrfora'tions, so that a dead air space is formed between the stove pipeand this outer cone, and the annular heating space above referred toformec between the two cones.

This arrangement prevents the possibility of soot, dislodged from thepipe above, coming out of the ventilating apertures of the stove pipe.The outer cone of my new co1nbination prevents soot from reaching theopenings, whereas? in the arrangement heretofore employed escape of sootfrom the annular perforations frequently occurred.

A. further novel feature of my invention is found in the inwardly curvededge or flange at the upper end of the cone. By means of this flange thegases are guided and delivered in a central stream upwardly.

1926. Serial No. 126,156.

through the middle part of the stove pipe, and anything falling throughthe pipe from above, will be prevented by this flange from falling intothe annular space between the cones. Such dislodged material will droping shown as communicating with a ven-,

tilating hood, which may be used for removing vapors from over cookingranges and the like.

Fig. 2 is a perspective view of the sliding annular band that surroundsthe ventilating opening of the stove pipe.

As is clearly shown in the drawings, the stove pipe damper andventilator to which my invention is applied consists of the length ofstove pipe 1 formed with an annular series of perforations 2 andprovided with the internal groove. 3, together with the usual truncatedhollow cone 4, open at top and bottom, and provided at its lower endwith a bead 5 adapted to be received in the groove 3. A band or ring 6,formed with perforations 7 is slidably mounted on the pipe 11 so as toopen and close the perforations.

The structure by which I accomplish the improved results above mentionedconsists in a conical member 8, open at the top and bottom, and havingits bottom edge beaded as at 9. The bead is received in an internalgroove of pipe 1, the groove being located top of cone 4 the heated airascends through.

the middle of the pipe and is mixed with the hotgases that have ascendedthrough the pipe and have been delivered through cone 8. Between cone 8and the wall of pipe 1 is formed an annular chamber 12 that is normallyfilled with gases that are not subject to violent circulation.Consequently the space 12 comprises a heat-retarding chamher, thefunction of which is to reduce the escape of heat from the wall of cone8 to the shell of pipe 1 and, therefore, the air of the annular space 11absorbs and retains the heat that is transferred to it from the walls ofthe hot gasconducting cone at.

The upper end 13 of cone 8 is flanged in- Wardly, as shown in Fig. 1,the diameter of the resultant opening being about equal to the diameterof the upper end of cone 1.

Soot or other substances that drop down through the stove pipe fromabove are prevented from escaping through the openings 2 and thusgetting into the apartment because the seam formed by bead 9 and groove10 prevents the soot from dropping down through space 12 and theinwardly projecting flanges 13 assure that any soot that drops throughcone 8 will pass on down through cone 4 and pipe 1.

If desired, the band 6 can be enclosed by an annular hollow casing 14;mounted on pipe 1 and the casing may be connected to a suitableventilating hood 15 by means of a conductor pipe 16. This hoodarrangement is convenient in connection with my improvement when thedevice is used for removing gas and odors from the top of a cookingrange, or for any similar purpose.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. The combination with a stove pipe damper having a conical member openat both ends and secured at its larger end to the interior of the stovepipe and having an air inlet damper located above said large end, asecond similar cone secured within said'pipe above said damper andenclosing a conical annular chamber communicating with said damper, theupper end of said sec ond cone projecting above said first mentionedcone and formed with a curved inwardly directed flange.

2. The combination witn a stove pipe damper having a conical member openat both ends and secured at its larger end to the interior of the stovepipe and having an air inlet damper located above said large end, of asecond similar cone secured within said pipe above said damper andenclosing a conical annular chamber communicating with said damper, theupper end of said second cone projecting above said first mentioned coneand forming a central gas and air mixing chamber enclosed within saidpipe.

In testimony whereof I afiix my signature.

BRUNO hLtARTIN.

